/*      $NetBSD: tokenizer.c,v 1.7 2001/01/04 15:56:32 christos Exp $   */

/*-
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Christos Zoulas of Cornell University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "compat.h"
#if !defined(lint) && !defined(SCCSID)
#if 0
static char sccsid[] = "@(#)tokenizer.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: tokenizer.c,v 1.7 2001/01/04 15:56:32 christos Exp $");
#endif
#endif /* not lint && not SCCSID */

/*
 * tokenize.c: Bourne shell like tokenizer
 */
#include "sys.h"
#include <string.h>
#include <stdlib.h>
#include "tokenizer.h"

typedef enum {
        Q_none, Q_single, Q_double, Q_one, Q_doubleone
} quote_t;

#define IFS             "\t \n"

#define TOK_KEEP        1
#define TOK_EAT         2

#define WINCR           20
#define AINCR           10

#define tok_malloc(a)           XMALLOC(0, a)
#define tok_free(a)             XFREE(0, a)
#define tok_realloc(a, b)       XREALLOC(0, a, b)


struct tokenizer {
        char    *ifs;           /* In field separator                    */
        int      argc, amax;    /* Current and maximum number of args    */
        char   **argv;          /* Argument list                         */
        char    *wptr, *wmax;   /* Space and limit on the word buffer    */
        char    *wstart;        /* Beginning of next word                */
        char    *wspace;        /* Space of word buffer                  */
        quote_t  quote;         /* Quoting state                         */
        int      flags;         /* flags;                                */
};


private void tok_finish(Tokenizer *);


/* tok_finish():
 *      Finish a word in the tokenizer.
 */
private void
tok_finish(Tokenizer *tok)
{

        *tok->wptr = '\0';
        if ((tok->flags & TOK_KEEP) || tok->wptr != tok->wstart) {
                tok->argv[tok->argc++] = tok->wstart;
                tok->argv[tok->argc] = NULL;
                tok->wstart = ++tok->wptr;
        }
        tok->flags &= ~TOK_KEEP;
}


/* tok_init():
 *      Initialize the tokenizer
 */
public Tokenizer *
tok_init(const char *ifs)
{
        Tokenizer *tok = (Tokenizer *) tok_malloc(sizeof(Tokenizer));

        tok->ifs = XSTRDUP (0, ifs ? ifs : IFS);
        tok->argc = 0;
        tok->amax = AINCR;
        tok->argv = (char **) tok_malloc(sizeof(char *) * tok->amax);
        if (tok->argv == NULL)
                return (NULL);
        tok->argv[0] = NULL;
        tok->wspace = (char *) tok_malloc(WINCR);
        if (tok->wspace == NULL)
                return (NULL);
        tok->wmax = tok->wspace + WINCR;
        tok->wstart = tok->wspace;
        tok->wptr = tok->wspace;
        tok->flags = 0;
        tok->quote = Q_none;

        return (tok);
}


/* tok_reset():
 *      Reset the tokenizer
 */
public void
tok_reset(Tokenizer *tok)
{

        tok->argc = 0;
        tok->wstart = tok->wspace;
        tok->wptr = tok->wspace;
        tok->flags = 0;
        tok->quote = Q_none;
}


/* tok_end():
 *      Clean up
 */
public void
tok_end(Tokenizer *tok)
{

        tok_free((ptr_t) tok->ifs);
        tok_free((ptr_t) tok->wspace);
        tok_free((ptr_t) tok->argv);
        tok_free((ptr_t) tok);
}



/* tok_line():
 *      Bourne shell like tokenizing
 *      Return:
 *              -1: Internal error
 *               3: Quoted return
 *               2: Unmatched double quote
 *               1: Unmatched single quote
 *               0: Ok
 */
public int
tok_line(Tokenizer *tok, const char *line, int *argc, char ***argv)
{
        const char *ptr;

        for (;;) {
                switch (*(ptr = line++)) {
                case '\'':
                        tok->flags |= TOK_KEEP;
                        tok->flags &= ~TOK_EAT;
                        switch (tok->quote) {
                        case Q_none:
                                tok->quote = Q_single;  /* Enter single quote
                                                         * mode */
                                break;

                        case Q_single:  /* Exit single quote mode */
                                tok->quote = Q_none;
                                break;

                        case Q_one:     /* Quote this ' */
                                tok->quote = Q_none;
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_double:  /* Stay in double quote mode */
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_doubleone:       /* Quote this ' */
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return (-1);
                        }
                        break;

                case '"':
                        tok->flags &= ~TOK_EAT;
                        tok->flags |= TOK_KEEP;
                        switch (tok->quote) {
                        case Q_none:    /* Enter double quote mode */
                                tok->quote = Q_double;
                                break;

                        case Q_double:  /* Exit double quote mode */
                                tok->quote = Q_none;
                                break;

                        case Q_one:     /* Quote this " */
                                tok->quote = Q_none;
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_single:  /* Stay in single quote mode */
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_doubleone:       /* Quote this " */
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return (-1);
                        }
                        break;

                case '\\':
                        tok->flags |= TOK_KEEP;
                        tok->flags &= ~TOK_EAT;
                        switch (tok->quote) {
                        case Q_none:    /* Quote next character */
                                tok->quote = Q_one;
                                break;

                        case Q_double:  /* Quote next character */
                                tok->quote = Q_doubleone;
                                break;

                        case Q_one:     /* Quote this, restore state */
                                *tok->wptr++ = *ptr;
                                tok->quote = Q_none;
                                break;

                        case Q_single:  /* Stay in single quote mode */
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_doubleone:       /* Quote this \ */
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return (-1);
                        }
                        break;

                case '\n':
                        tok->flags &= ~TOK_EAT;
                        switch (tok->quote) {
                        case Q_none:
                                tok_finish(tok);
                                *argv = tok->argv;
                                *argc = tok->argc;
                                return (0);

                        case Q_single:
                        case Q_double:
                                *tok->wptr++ = *ptr;    /* Add the return */
                                break;

                        case Q_doubleone:   /* Back to double, eat the '\n' */
                                tok->flags |= TOK_EAT;
                                tok->quote = Q_double;
                                break;

                        case Q_one:     /* No quote, more eat the '\n' */
                                tok->flags |= TOK_EAT;
                                tok->quote = Q_none;
                                break;

                        default:
                                return (0);
                        }
                        break;

                case '\0':
                        switch (tok->quote) {
                        case Q_none:
                                /* Finish word and return */
                                if (tok->flags & TOK_EAT) {
                                        tok->flags &= ~TOK_EAT;
                                        return (3);
                                }
                                tok_finish(tok);
                                *argv = tok->argv;
                                *argc = tok->argc;
                                return (0);

                        case Q_single:
                                return (1);

                        case Q_double:
                                return (2);

                        case Q_doubleone:
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_one:
                                tok->quote = Q_none;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return (-1);
                        }
                        break;

                default:
                        tok->flags &= ~TOK_EAT;
                        switch (tok->quote) {
                        case Q_none:
                                if (strchr(tok->ifs, *ptr) != NULL)
                                        tok_finish(tok);
                                else
                                        *tok->wptr++ = *ptr;
                                break;

                        case Q_single:
                        case Q_double:
                                *tok->wptr++ = *ptr;
                                break;


                        case Q_doubleone:
                                *tok->wptr++ = '\\';
                                tok->quote = Q_double;
                                *tok->wptr++ = *ptr;
                                break;

                        case Q_one:
                                tok->quote = Q_none;
                                *tok->wptr++ = *ptr;
                                break;

                        default:
                                return (-1);

                        }
                        break;
                }

                if (tok->wptr >= tok->wmax - 4) {
                        size_t size = tok->wmax - tok->wspace + WINCR;
                        char *s = (char *) tok_realloc(tok->wspace, size);
                        /* SUPPRESS 22 */
                        int offs = s - tok->wspace;
                        if (s == NULL)
                                return (-1);

                        if (offs != 0) {
                                int i;
                                for (i = 0; i < tok->argc; i++)
                                        tok->argv[i] = tok->argv[i] + offs;
                                tok->wptr = tok->wptr + offs;
                                tok->wstart = tok->wstart + offs;
                                tok->wmax = s + size;
                                tok->wspace = s;
                        }
                }
                if (tok->argc >= tok->amax - 4) {
                        char **p;
                        tok->amax += AINCR;
                        p = (char **) tok_realloc(tok->argv,
                            tok->amax * sizeof(char *));
                        if (p == NULL)
                                return (-1);
                        tok->argv = p;
                }
        }
}
